Contacts for electrical devices



United States Patent O CONTACTS FOR ELECTRICAL DEVICES 'Vernon Hellstern, St. Louis, Mo., assignor 'to James R. u Kearney Corporation, St. Louis, Mo., a corporahon of Missouri v Application May 31, 1951, Serial No. 229,()55

3 Claims. (Cl. 339-64) 2,738,478 Patented Mar. 13, 1956 link is ruptured, becauseof the presence of an electrical fault in the circuit in which the cutout A is interposed, the fuse cartridge drops downwardly to the position in which it is shown in Fig. 2.

The cutout A is provided withan upper incoming contact structure 13 and a lower outgoing contact structure 14 which are engaged by portions of the fuse cartridge 6 so as to bridge the gap between said contact structures. The upper contact structure 13 comprises a strip of metal, or other material, which is characterized by being a good conductor of electricity. The strip is shaped as is shown to good advantage in Figs. 1 and 2 to provide a contact member 15; that is to say, said strip includes a vertically disposed portion 16 from the upper end of which a rearwardly extended, horizontal portion 17 is projeeted, a vertical portion 18 that extends upwardly from the rear end of said horizontal portion 17 and which merges into an upper, horizontal, forwardly extended portion 19, a portion 20 which extends downwardly from the forward end of said upper portion 19 and which merges into a forwardly extended portion 21. The portions 16 and 20 i are Secured together by a pair of rivets 22, and said por- Fig. 2 is a fragmentary vertical sectional View similar to Fig. 1 but showing the fuse cartridge of the cutout in the open-circuit position.

Fig. 3 is a fragmentary horizontal sectional view taken online 3-3 of Fig. 2.

`Fig. 4 is a front elevational View illustrating the contacts of the cutout shown in Figs. 1 and 2.

' In the drawings wherein is shown for purposes of illustration, merely, one embodiment of the invention, A designates an electrical cutout of the housed type having a housing 1 formed of porcelain, or other suitable electrcal ta 5.formed in the top wall of the housing 1 so as` to latch i the door in its closed position with respect to the' housing 1.

For the purpose of illustrating the use of the present invention the door 2 has mountedthereon a fuse cartridge '6. which is supported for vertical movement 'by an extension 2' that is projected rearwardly from the door 2, a portion of the tube structure 7 of the fuse cartridge 6 being extended through anopening 8 formed` through the extension`2'. The fuse cartridge 6 is provided with an upper portion 9 of increased diameter, an annular shoulder 10 being provided at the bottom of said upper portion 9 which serves as an abutment that engages the top face of the extension 2' and limits downward movement of the fuse cartridge when saidfuse cartridge moves toward the open-circuit position (see Fig. 2). The fuse cartridge is provided with a cap 11 that 'screws on an upper portion of the tube structure of saidfuse cartridge and clamps the upper portion of a fuse link 12 within the upper part of said tube structure. The fuse link passes downwardly through the tube structure of the fuse cartridge and at its 'lower end said fuse link is attached to mechanism (not shown) whereby said fuse link, when intact,`serves to retain the fuse cartridge in the elevated position in whichit is shown in Fig. 1. However, when the fuse tion 21 has formed theren an oifset portion 23 and is provided at its forward end with an upwardly and forwardly inclined portion 24. The portion 20 of the contact 13 has formed therethrough a pair of screwthreaded openings in which are supported for screwthreaded adjustment clamping screws 25, which serves a purpose to be hereinafter set forth.

The rear wall of the housing 1 has formed therein an opening 26 in which is disposed a socket member 27, said socket member being provided with a screwthreaded opening 28 and having annular ribs 29 formed exteriorly thereof. The socket member is secured in place within the opening 26 by being embedded in a body 30 of lead, or other suitable material, which is disposed in said opening 26. The structure `of the upper contact 13 includes a channel-shaped member 31 which serves as a base member and' is disposed against the inner face of the rear wall portion of the housing` in which-the opening 26 is formed, the opposed side flangesof said channel-shaped member being projected forwardly, as is shown to good advantage in Fig. 3. The channel-shaped member has an opening 32 formed therethrough through which the shank portion of a bolt'33 is extended, the rear portion of said bolt shank being screwed into the screwthreaded opening 23 of the socket member 27. The bolt 33 is provided with a head portion 33' and embracing the shank portion of 'said bolt is a sleeve 34 which contacts at one of its ends with the inner face of the head portion of the bolt and at its opposite end with a forward face of the channelshaped member 31. Arranged in embracing relation with respect to the sleeve 34 is a coil spring 35, said coil spring contacting at one end thereof with the forward face of the portion 16 of the contact member 15 and' at its opposite end with the inner face of the head portion 33' of the bolt 33.

The lower contact structure 14 resembles the upper contact structure 13 in Construction and arrangement in that it includes an externally ribbed socket member 36 which is leaded in an opening 37 formed in the rear wall of the housing 1. The socket member 36 is provided with a' screwthreaded opening that receives a portion of the shank of a bolt 38, said bolt shank being extended through an opening 39 formed through'a vertical portion 40 of a strip of material which produces the contact menber 41 of the contact structure 14, and through an opening formed through a wall of a channel-shaped member 42 which serves as a base member. A portion of the shank of the bolt 38 is embraced by a sleeve 43 which contacts at one of its ends with a wall of the channel-shaped mem- -3 ber 42--and -at=its*opposite end wth--the inner face -of 'the head 38' of the bolt 38, said sleeve in turn being embraced by a coil spring 44 "which contacts at one end thereof` with the forward `'fa`ce"of'*the 'vertical portion` 40 of the' 'cohtaet memberrandafits'oppdsite'end with'the inner faceof'theheadof the bolt `38.

The strip of material which*prdcluces 'the contact member"'4 1` 'in clu d es 'horizontal portion* 45 t that 'exterids'rearwardly from'the lowe==portion of "the vertical'portionm, a vertc abportion 46"which" extends downwardly from the 'inner'en'd'f said'horizontal *portion 45, a'horizontal por'tion-'-`47that 'exten'ds forwardlyfrom the lower end of' said vertical" portion-"46, *a vertical' portion-' 18 'which extends ur'n'vai-'dly 'from the forward' end of `-the' horizontal portion 47, and a* portion-`49 that extends forwardly from the upper :portionar the vertical' portion '48. "T-he portions 40`-and*48-*are secured'ogther by means'f-pair of rivets tl, and the extremempwardly curved, forward end of the 'porti0n' 49 f the' contact member-41-is provided `with ame'eess 51. Also`,-- the vertic`al portion 48 has a pair of screwthreaded* pehings' 52 'fornedtherthrou'gh which screwthreadedly *receivesklampingscrews 53 that serves a purpose to be hereinafterset forth.

As' -has been' pre iously stated-harem, 'the' `fuse' link' 12 serves, when int-actfto maintain the fuse cartridge 6-^in an elevated position with respect to the'=` door Z-and when said door is 'closedand 'the fuse Cartridge is in such clevated 'position' the cap' ll of th fuse Cartridge 'Contacts with thecO'nt-act member of theupper contact structure 13, While the-shoulder@=of-said fuse' Cartridge conta'cts with the contact member of the -lowercontact structure 14, as is shown in Fg. 1. It is mportaht to note 'th'at-when the fuse cartrid'ge is' in -its circ'iFclosing' `position, as is shownin 'Fig. l, the"-upper-` contact" member 1'5 and' the lower contact memb'er ll' are 'ca'nted sli ghtly in an upward direction, the 'coil springs ssan'd `44 ot the upper and lower' contact' structures `permitting su'ch- -canting 'of-'said contactmembe'rs. Asa result oflthe canting of the'contact` membersof the upper and lower contact struotu-es very intimate contactisobtained betwen the contact members and 'the portio ns -ot :the fuse -cartrdge with which: 'said contact memb'ers contact becauseof the force exerted by the coil springs :35 and 44. v Also, because the incoming: 'anda outgoing.:electrical: conductors Ca' and Cb -are `clamped oiretly to the:contact members: of the upper and lower:contactetrncures 13 and 14' by the clamping screws;zs andsathe electrical connection between sadelectrical conduetorsand the Lfuse cartridge' is about as,:perfect=" 'asnit SPOSSbIC O HIakCy'QS the o'nly places -wheretransfers ofi current between 'contactingparts takesplace s'-wh'ere:the=contact `member ofathe upper conta'ct structure 13 eontacts wvithlthe capl11 of thefuse cartridge, iand where:the' contactmemb'erofr the :lower contact structu-e" 14 contacts' with .the'shoul'deri 6 i ofthe use Cartridge, and:the contact*engagements at these points-are made very 'intimate becauseof the 'forces'exerted by' the 'coilsprings 35 a d"`44.

When, in the `use-..tf::theilIustratd Iswitch :disclosed heren the' fuse *link 1.2:is:ruptured,'the fusecartridge '6 drops downwardly, thereby separating the cap.-11 'and the shoulder 6' of the fuselink fromthe contactmernbers of the upperand lowercontact structures13zand 14. and interrupting the circuitih-which the switch =is interposed. lt is to be .noted thatthe coil :springs 35 and- 44 o'fiithe upper and lower. contactrstructures 13 and 14. fa'cilitate such downward movement of :the fse 'cartridge6, because said coil springs exert: downwardly ldrec'ted' 'forces against parts of said fuse Cartridge. 'Whenthefuselinkn usein the 'switch' has been ruptured, sas :described :abovethe door 2 is opened and 'removedufrom .thethousinggafter which-a. new fuse linkis .introduced in place .in:the:fuse Cartridge so that it..retains.thefuse cartridge` in. its.elevatd positon with respect lto thedoor. The-door 2 :is then replac'ddn associationwith the housing 1 and is closed in ofl'thhouing, `the cap ll and the sholder 6' -ofwthe fuse eartridge ridingunder .the contact.-members of the upper and lower contact structures 13 and 14 and moving their outer end portions upwardly slightly, and the latch element 3 eventually latches the door 2 in its closed position.

I claimr 1. A contact structure for an electrical device comprising a'contact member, -means for movably 'supporting said contact member, said supporting means comprising a-serewthreaded element having an abutment, a so`cket member for screwthreadedly receiving a portionuofsaid screwthreaded element, a base member having an opening through"whi'ch"said screwthreadedelement"eXtends,-=a separate sleeve embracing a portion of said screwthreaded element, said sleeve Contacting at one end thereof with said abutment of said screwthreaded element and at its opposite end With said base member, a coil spring embracingsaid-s1eeve an'dcontacting at one'of 'its ends-'with said abutment 'f saidscrewthreaded-element and at-its opposite end' witha portion ofsaid. contact member -to' which said'cih'spring applies pressure, and means for'connecting=anelectr`ic`al conductor directly to said contact member.

2. A contact-structure for an electrical device comprising a'cont-act member formed' from a-single length of '-'materal' shaped--'to provide a substantiallyve'r'tic'al portion and`-asubstantially horizontal portion, I means-for movablysupportng said contact member, said "supporting means comprising a screwthreaded element havng an abutmenh a sock'et member for screwthreadedly' receiving=a pdrti'on of said-screwthreaded element aachannel-shaped base member having anopening through which *said '-'screwthreaded v element 'extends, a separate sleeve embracing a portion of said 'screwthreaded elemeht,'- s`aidsleeve* contacting at one' end -thereof with s'aid abutment of said screWthreaded-elem'ent and at 'its opposite'end with.-` said' base member, a coil spring embracing said' sleeve 'atidcontactingat one of its ends'with said abutment of- 'said' screwthreaded element and at its' opposite end wi'th'a portion of said contact member to' whch saidcoil sprin'g 'applies 'pressure, -`and v means 'for z connecting 'an i electricalz conductor directly to said. :contact member.

3.-- A contact 'structure for an `eleotrical I device comprising a contact member formed from a single. length of material-'shaped to 'provide a substantially- Vertical portion and-' a' subst antially horizontal portion; means for movably: supporting said contact member, :said supporting 'means' comprising a screwthreaded element'-'which .is extendedathrough an opening formed' through 'ai-.portion ofisaid contact member and having an: abutmenhvazsoclret member for screwthreadedly receiving a portion ofsaid screwthreaddelement, a channel-shaped base zmember hawngmnopeningthrough whichsaid screwthreadedsele'- menteXtends, a separate 1 sleeve embra'cing a :portion of saidscrewthreaded element, said sleeve contactingmtone endithereofxwith-said abutment .of saidscrewthreaded elementbandatiitsopposite end with said base member, acoil spring''embracing: said -sleeve and conta cting at one of -itsendswith-said abutment of said screwthreadedelement andatits oppositeend with a portion of said contact memberato which .said coil spring v applies' pressure, and` meansfo' connectng an electrcal conductor: directly to :said contactmember.

i References Cited in the file ofthis patent r UNITED STATES PATENTS "93`O,T96 Krotz Augfj 1909 ',I,72,604 Jhnson "Feb.l"22, 1916 ',l,l93 -,51` 3 Chryst Aug. 8, 1916 l',82 5,`1'30 Schneider Sept. 29, 1931 1364283 "Steinmayer u June 21,' 1932 "2,l 54, 689 Mt thews etvl. Apr. "1 8,"l 939 2`, l'9`,007 Christensen Apr. 15,'19'47 

